Check-List of North American Batrachia and Reptilia; With a Systematic List of the Higher Groups, and an Essay on Geographical Distribution - Based on the Specimens Contained in the U. S, National Museum #260869

The present contribution to North American Herpetology is a prodro mus of a general work on that subject, undertaken some years ago at the request of the Secretary of the Smithsonian Institution. The mate rial which has been accumulating in the museum of that Institution has offered great advantages for the investigation of the questions of anatomical structure, variations of specific characters, and geographical distribution. It is believed that these subjects are much elucidated by the study of the Batrachia and Reptilia, since these animals are especially susceptible to physical influences; since, also, they are unable, like birds, and generally not disposed, as are mammals, to make extended migra tions, their habitats express nearly the simplest relations of life to its surroundings.